Year	%
1988	15.61
1991	11.53
1993	9.76
1996	6.43
1997	5.75
1998	5
1999	4.89
2000	4.64
2001	5.22
2002	5.14
2003	5.12
2004	4.99
2005	4.79
2006	4.49
2007	4.68
2008	5.03
2009	5
2010	4.15
2011	4.4
2012	4.67
2013	4.48
2014	4.33
2016	4.28
2020	3.85
2021	3.88